1. Field of the Invention
The invention generally relates to electronic circuits for limiting the inrush current in DC to DC and DC to AC power supplies and more particularly to an inrush current limiting circuit for controlling inrush current surges resulting from LC filter configurations in DC to DC or DC to AC power supplies.
2. Background of the Invention
LC filters utilized in DC to DC and DC to AC power supplies inherently cause large inrush currents which are usually suppressed with dissipative components, adding to the cost and complexity of these power supplies.
Utilization of Field Effect Transistors (FET) in current limiting/regulating power supplies is well known in the prior art patent literature as exemplified by U.S. Pat. No. 4,814,687 to Walker in which a FET is placed in series between the voltage source and the load. Regulation/limiting is achieved by control electronics which vary the effective "on" resistance of the FET. Further exemplary of inrush current limiting circuits where a FET is utilized as the control transistor is U.S. Pat. No. 4,849,683 to Flolid. Also, inrush current limiting is further exemplified by U.S. Pat. No. 4,207,516 to Babcock.